The influence of soil electrical parameters on the electric field due to power line communications: Measurements of frequency-dependent soil parameters

The contribution of the present work is to demonstrate the influence of soil electrical parameters (conductivity and permittivity) on the electric field generated by power line communications (PLC). Soil samples were collected from beneath the high-voltage transmission lines under investigation and analyzed in the laboratory using a simplified method of measuring scattering parameters. These were converted into ABCD parameters in order to obtain the characteristic impedance and then the complex permittivity as a function of frequency. The employed methodology to find the soil electrical parameters as a function of the frequency was compared to the Smith and Longmire model, which is appropriate for modeling in the frequency range of PLC signals. The results obtained by both models for calculating the electrical parameters were applied to the electric field equations developed by D'Amore. Although high-voltage transmission lines generally use narrowband PLC for control system operations, the present work implemented both narrow and broadband analyses.